Is there a known/common GPS date/time bug recently?

[Chris Green]

I have a Panasonic TZ60 camera which has GPS for setting the location of pictures taken. It also allows you to use the GPS to set the date and time that pictures have been taken.

However a few weeks ago (maybe more, but this year I think) it has suddenly started getting the date completely wrong, today (17th June

2023) it says the date is 1st November 2003. It's still getting the time right. The camera's date changes 'correctly' in that its date is a constant period (of almost 20 years) behind the right date.

I've done a bit of web searching but I can't find anything directly relevant but there are some reports of SatNavs which have a bug that produces similar symptoms.

Does anyone know if this is a known bug/problem and if there's a fix or workaround?

[charles]

does it have an internal battery? It might be worth replacing it if there is one.

[Chris Green]

It's a rechargeable battery that runs eveything in the camera, the state of charge doesn't seem to affect the date problem.

[John]

Can you reset the time and date manually and then allow the GPS to keep it in time?

Does the GPS time code recycle after 19+ years?

[Colin Bignell]

Is it in a location where it has a clear view of the sky, to be able to pick up the satellite signals?

[alan_m]

Is the cameras getting its time from a real time clock that is running

24/365 and just being corrected by GPS when available?

How long are you leaving the camera on to find the GPS?

If the camera doesn't have A-GPS (assisted GPS) and if you have moved the camera to a significantly different location and/or the camera has lost the GPS* it may take anything from 10 to 30 minutes to acquire the initial configuration data. Plus the camera probably needs to be outside with a clear view of the sky for this 10 to 30 minutes.

Devices with a A-GPS uses a different method, such as mobile phone towers, to get a rough fix first to enable the GPS device to obtain a very fast GPS fix.

I had an early version of TomTom Sat Nav on a Dell PDA and had slow initial GPS data (up to 20 minute delay) if I had driven a fair distance with the Sat Nav turned off. The crude A-GPS on that device was to bring up the map and to manually tell the device the current location.

*maybe you turned off GPS a lengthy period of time (a month or more) for camera storage to maintain the battery or the battery when flat.

maybe....

It seems that Panasonic may have discontinued a A-GPS feature on May 31,

2021

[Paul]

They have the NMEA sentences here, for reference.

At least one of them looks interesting.

$GPZDA,UTC,DD,MM,YYYY,TH,TM,*CS<cr><lf>

^^^ ^^ ^^ ^^^^

Perhaps this is more common. This does not have DD MM YYYY.

$GPGGA,UTC,LAT,LAT_REF,LON,LON_REF,FIX_MODE,SAT_USED,HDOP,ALT,ALT_UNIT,GEO,G_UNIT,D_AGE,D_REF*CS<cr><lf>

I think mine dumped about four messages a second. But I don't know if I recorded a sample of that anywhere. (It's not running right now.)

Using the position fix, the software should be able to determine the TZ and DST and compute a "local" time instead of UTC.

Paul

[Chris Green]

If I set it manually then the GPS changes is back to November 2003. I can disable the GPS setting of the time completely but that means I'm relying on me and the camera to remember the date!

That's about the 'wrongness' I'm seeing and I think some of the SatNav errors were of this sort of size.

[Chris Green]

Oh yes, it's getting the location OK. Anyway this has happened several times, both in the UK and here (I'm in France at the moment). The time setting has worked perfectly for several years and now it has suddenly gon crazy.

[Chris Green]

If I set the time correctly then, after a while, when the GPS finds a signal it sets it back to November 2003. It's very obvious!

It's not like this. The GPS actually changes the date from the correct date to the wrong one, it's not a case of waiting for the GPS to get it right, quite the opposite!

That sounds like exactly what I'm seeing.

Yes, it's difficult to work out what this means exactly. I'm sure my camera's date was OK quite a longtime after that, into 2023 at least.

[Andy Burns]

The GPS week number rolls-over every 1024 weeks, it's only happened twice so far since GPS has existed, aug 1999 and apr 2019.

[nib]

Highly suspicious though, as the difference between today 2023-06-17 and the wrong date it maps to 2002-11-01 is exactly 7168 days or 1024 weeks!

nib

[mm0fmf]

It is a classic week rollover issue. Some programmers have clue, they know when they were writing the software and know the date from GPS cannot be from before the software was written. So if they knew they were writing it in 2013 and GPS rollover says the date is before 2013 they know to add 1024 weeks. Even better programmers allow you to enter the date and work out how many GPS rollovers there have been and save that data. Then the know whether to add 1x1024, 2x1024 etc. to the date.

Your choices are

• update the software if available (unlikely)

• stop using the GPS assist

• buy a new camera

[Brian Gaff]

Yes, back when I could see I had a 35mm camera that could print very small date time right on the edge of the negative. It was made by Pentax, and that had date issues if the battery was going, long before the battery showed any issues on photos or winding film.

Brian

[Chris Green]

Ah, thank you. While that sounds as if it might plausibly be the root cause of my problem it seems a bit unlikely as my camera was putting the right date on pictures right through from when I bought it in 2016 to at least a fair way into 2022 and probably into 2023.

However it does look like it's something to do with it as the date error is exactly 1024 weeks, the camera thinks it's November 2nd 2003 today which is 1024 weeks ago.

Whether it's fixable is another matter of course!

[Chris Green]

There is another option, fortunately. I can turn off the date setting from GPS and simply set date/time manually. I'm not sure how accurate the camera's clock is (I'm going to find out) but I guess it should be fairly accurate and so I'll just need to check every few weeks or so.

[mm0fmf]

That's option 2, "stop using the GPS assist".

I have a Panasonic TZ20 on which I have never used the GPS on and a TZ100. The clock was set by hand. If you leave either with the battery installed and don't use them for a while you find the batteries are flat. I open the door and remove the batteries now. After some weeks the TZ20 asks for you to set the clock. I've not left the TZ100 long enough for it to want the clock setting.

I went and turned on the GPS on on the TZ20 for the first time and after about a minute it was able to tell me the time and date with position. It defaults to 2011 when you need to reset the clock, so it's quite old. But the GPS got the year right at 2023. YMMV

[Thomas Prufer]

ISTR a Panasonic camera that had a file with AGPS data it liked to have refreshed form time to time...

Ah, ok: it's been discontinued:

Thomas Prufer

[Thomas Prufer]

My google found that some Panasonic laptops have a similar problem. They offer a software fix -- no good to you! -- but it reinforces the view that it's something the Panasonic GPS programmers missed.

Thomas Prufer

[maus]

There was a stoory about a month ago that robot tractors in the US midwest had problems with their GPS